Lesson: Boyle’s Law High School Physics

Physics

In this lesson, we will learn how to use the formula PV = constant (Boyle’s Law) to calculate the pressure or volume of a gas that is allowed to expand or contract at a constant temperature.

Plan

Objectives

Students will be able to

know that for an ideal gas at constant temperature, the pressure, , of the gas is inversely proportional to the volume, ,
use , where is a constant, to determine the pressure or volume of a gas before or after a thermodynamic process that keeps the temperature constant,
understand diagrams that represent the particles of a gas and how Boyle’s Law can be shown using these diagrams.

Prerequisites

Students should already be familiar with

pressure,
volume,
density,
temperature,
states of matter,
the idea that substances are made up of particles.

Exclusions

Students will not cover

Gay-Lussac’s law,
Charles’ law,
the ideal gas law,
the kinetic theory of gases,
internal energy,
entropy,
phase changes.

Video

13:26

Sample Question Videos

05:31
04:35
06:16

Worksheet

Q1:

A bike tire is pumped up using a foot pump. The pressure of the gas within the tire increases, but the volume remains the same. What happens to the temperature of the gas?

Q2:

A sphere of gas expands from a radius of 0.5 m to a radius of 2 m. The temperature remains constant throughout. How many times smaller is the pressure of the gas in the sphere after its expansion?

Q3:

At sea level on Earth, the atmospheric air pressure is about 101 kPa. At the top of Mount Everest, the air pressure is about 34 kPa. A balloon with a fixed amount of helium gas is taken from sea level up to the top of Mount Everest. The temperature of the air is the same at both locations. What happens to the size of the balloon?

Preview